intel: Add a little OpenCL C compiler binary

v2: Fix up indentation (Marcin)
    s/gen/gfx/ (Marcin)
    Deal with fd closing in success/fail cases (Marin)

Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/13171>

meson_options.txt

@@ -509,3 +509,9 @@ option(
   value : false,
   description : 'Build vulkan drivers with BETA extensions enabled.'
 )
+option(
+  'intel-clc',
+  type : 'feature',
+  value : 'disabled',
+  description : 'Build the intel-clc compiler (required for ray queries).'
+)